Feed-water heater.



T. E. GRAHN.

FEED WATER HEATER. APPLICATION FILED MAR.7, 1910.

Patented Oct. 24,1911.

2 SHEETS-SHEET 1.

F'IGJ.

INVENTOR,

COLUMBIA PLANDGR APH (20.. WASHINGTON. D. c.

-T. E. GRAHN. FEED WATER HEATER. APPLICATION FILED MAR.7, 1910.

Patented Oct. 24, 1911.

2 SHEETS-SHEET 2.

INVE'NTDR,

WITNESSES.

T Maw/Mu @M COLUMBIA PLANOGRAPM COWWASHINO'ION. D- C.

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THOR-WALD E. GRAHN, OF CLEVELAND, OHIO, ASSIGNOR OF ONE-THIRD TO LE GRAND PARISH, OF NEW YORK, N. Y., AND ONE-THIRD TO HENRY H. VAUGHAN, OF MON- TREAL, CANADA.

FEED-WATER HEATER.

Specification of Letters Patent.

Patented Oct. 24L, 1911.

To all whom it may concern:

Be it known that I, THORWALD E. GRAHN, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Feed-Water Heaters, of which the following is a specification.

The invention relates to feed water heaters and particularly to feed water heaters for locomotives. One of the objects of my improvement is the provision of a feed water heater of the class specified in which onlya small portion of the water in the tank will necessarily be heated, leaving the balance of the water at a lower temperature, so that if there is a tendency on account of the over heat of the water to interfere with the action of the injector, the injector on the other side which takes the water at lower temperature will not be interfered with.

Another advantage of the employment of the feed water heater provided with means for heating only the limited quantity of the water in the tank, is, that in this arrangement the water in said limited space will be very quickly heated, and will be held in proper temperature condition in spite of repeated refilling of the tank along the line.

Still another object of my improvement is, the provision of effective means for automatically controlling the heat, which will operate to maintain a temperature of a predetermined amount, say about 105 or 110 or whatever seems to give the best results, and is not sufficiently high to interfere altogether with the injector operation.

It will be evident that by my improvement I am enabled to use exhaust steam either from the engine itself, or from the air pump, and by the piping shown, the steam may come partially from both places, but the particular source of the steam employed is immaterial insofar as the broad invention is concerned.

A further object of this improvement is the provision of an automatic regulating means for governing the temperature of the water which is heated, of great accuracy and reliability. One embodiment of the invention is illustrated in accompanying drawing wherein- Figure 1 is a side elevation of a locomotive and tender with the feed water heater applied thereto,

Figure 2 is a side elevation of the apparatus as installed in the tender of the locomotive,

Figure 3 is the partial plan view of the tender showing the osition of the apparatus,

Figure 4 is an enlarged partial side elevation and partial sect-ion of the thermostatic controlling means in the tank, and

Figure 5 is an enlarged section on the line VV of Fig. 2.

The feed water heater is illustrated as applied to a locomotive, and certain of its fea tures are particularly advantageous in this connection, but it will be apparent that there are other features of invention which are of general application, and that the invention is not limited to the use of a feed water heater in the particular relation illustrated. In the preferred embodiment of the invention, exhaust steam is applied to heating the water in the tender by means of a connection to the exhaust of the air pump and to the exhaust cavity above one of the cylinders of the locomotive. This supply of exhaust steam to the water of the tank is controlled by means of a valve which is in turn automatically regulated by means of a thermostat in the tank, so that the water in the tank may be automatically maintained at a predetermined temperature. A heating compartment is also provided in the tank, so that only a portion of the water in the tank need be heated.

Referring to the drawings, the principal parts of the apparatusmay be enumerated as follows: 1 is the pipe for supplying the exhaust steam to the water in the heater, such pipe having a flexible connection at 2, and being connected at 3 with the steam exhaust cavity above one of the cylinders and at L with the exhaust from the air pump 5; 6 is the casing of the controlling valve, which casing is connected to the supply pipe 1; 7 is the heating compartment to which the exhaust steam is supplied, and which heating compartment is separated from the main tank in the manner indicated in Figs. 2 and 3; 8 is the thermostat located in the heating compartment 7; 9 is the casing of a pilot valve for controlling the operation of the controlling valve; 10 is the casing of the actuating means for the controlling valve in the casing 6; and 11 is the injector supply pipe leading from the forward end of the heating compartment 7.

As indicated in Figs. 2 and 3 the compartment 7 is located preferably at one side of the tank in the tender and is substantially surrounded by the water in the tank inasmuch as the sides 12 and 13 are spaced away from the sides of the tender. This arrangement of course increases the economy of the apparatus and very little heat is lost by radiation. A free flow of water from the tank to the compartment 7 may occur 1 through the flap valve 1 1, such valve being arranged as indicated in Fig. 2 to prevent a back flow from the compartment 7 to the main tank.

The means whereby the flow of steam from the pipe 1 to the compartment 7 is automatically regulated from the temperature of the water in said compartment constitutes an important feature of my invention and is indicated in detail in Figs. & and 5. From Fig. 5 it will be seen that the casing 6 is provided with a balanced valve 15, and that the stem of the valve carries an operating piston 16, such piston being normally held down by means of the spring 17 regulated by the screws 18. The piston 16 is operated from the thermostatic controlling means by means of a pilot valve having the connections 19 and 20 leading respectively to the inlet chamber of easing 6 (Fig. 5) and to the lower side of the piston 16. The flow of steam through these pipes 19 & 20 is controlled by the pilot valve 21, (Fig. 4) inclosed in the casing 9 and this pilot valve 21 is controlled from the thermostat in the manner to be hereinafter described. The thermostat may be of any approved type, but as is shown consists of a pair of hollow disks 22 and 23 filled with a liquid having a high coeflicient of expansion, such as ether. The upper vessel carries the operating rod 24 which rod is adapted to be moved up by the expansion of the fluid in the vessels and to be moved down by means of the spring 2 1 regulated in tension by means of the screw 25, and this rod 24 carries a lever 25 whose outer end has a lost motion connection with the stem 26 of the valve 21 at 31 so that as the water in the compartment cools and the rod 24 moves downwardly the left hand end of the lever 25 will move upward to open the pilot valve 21. The lever 25 is pivoted at 27 to the supporting stud 28, there being a lost motion at this point as indicated in the drawing, and also has pivotal bearing upon the point 29. A sliding plate 30 bears against this point or projection 29 and is yieldingly held in the position shown by means of this spring 31. The purpose of this latter arrangement is to prevent injury in the thermostat and valve in case the thermostatic disks expand too far, due to a back flow of steam from the injector or other cause, in which case the lost motion connection at 27 permits the lever 25 to 'move upward without throwing any addi ,tional strain upon the thermostat.

The lost motion connection at 81 is desirable in that it permits the valve 21 to move more rapidly from open to closed position when the water in the compartment reaches the desired temperature, and also to open more rapidly. This prevents wire drawing and the consequent cutting out of the valve seat.

The operation of the apparatus is as follows: The water in the compartment 7 being hot, the parts are in a position as indicated in Fig. 4:, the pilot valve being closed as well as the valve 15. If now the water cools below its predetermined point the rod 24; descends thus causing the valve 21 to rise whereupon the steam from the pipe 19 passes through the casing 9 to the pipe 20 and thence to the under side of the piston 16 (Fig. 5). The pressure thus applied to the piston 16 causes it to rise opening the valve 15, whereupon steam from the pipe 1 passes through the casing 6 and through the outlet pipe into the compartment 7. The steam continues to flow until the water reaches the predetermined point at which time the expansion of the thermostat causes the rod 24 to rise and thus secures the closing of the pilot valve 21 thus cutting 01f the supply of steam to the under side of the piston 16. The tension of the spring 17 then causes the piston 16 to descend and secures the closing of the valve 15.

The advantages of the construction will be apparent from the foregoing description. The arrangement of the steam inlet pipe at the rear end of the compartment 7 is advantageous in that the force of the incoming steam tends to carry forward the water through the compartment and thus lessens the work which the injector has to do in drawing water from such compartment. It will also be seen that the use of the heating chamber instead of heating the entire body of water in the tank, is advantageous because much more flexible and furthermore provides for a more rapid heating of the water and protects such water from undue cooling due to the refilling of the tank along the line. The arrangement also secures a more reliable operation of the injectors than would be the case if the entire body of water 3 were heated, as the heating of the water to a high temperature sometimes interferes with the operation of the injector, and where a portion of the water in the tank is cold, the other injector which is always used with a locomotive can be fed from this portion of the tank. It will also beseen that by the provision of an automatically regulated feed water heater, the operation of which will be so reliable and accurate the temperature of the water can be raised to the maximum temperature at which the injector will operate. In other words by reason of the reliability and accuracy of the operation of the apparatus, it is possible to maintain a uniform average temperature of the feed water considerably higher than would be safe or permissible in connection with apparatus which was of a cruder character and lacking in the automatic regulation.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is the following 1. In combination in a feed water heater, a main tank, a heating tank therein communicating therewith, a check valve for permitting an inflow into the heating tank from the main tank but preventing a back flow, steam heating means for supplying heat to the heating tank, and an outlet from the heating tank.

2. In combination in a feed water heater, a maintank, a heating tank therein, at one side of the main tank, with its side spaced away from the side of the main tank and its top lying beneath the surface of the water in the main tank, means for permitting an inflow into the heating tank from the main tank, steam heating means for supplying heat to the heating tank, and an outlet from the heating tank.

3. In combination in a water heater for locomotives, a main tank, an auxiliary tank located in the main tank and surrounded by the water of the main tank, a communication permitting a free flow of water from the main tank to the auxiliary tank, a check valve for preventing a back flow through such connection, a steam pipe for supplying heat to the auxiliary tank, a controlling valve in the said pipe, a pilot valve communicating with the steam pipe for controlling the operation of the controlling valve, a thermostatic meansin the tank for controlling the operation of the pilot valve, and an injector supply pipe leading from the auxiliary tank.

4. In combination in a feed water heater, a main tank, an elongated heating compartment in such main tank in communication therewith, a forwardly directed steam pipe opening into the compartment, and an injector outlet adjacent the front end of the compartment.

5. In combination in a feed water heater for locomotives, a main tank, an auxiliary tank extending along one side of the main tank and surrounded by the water therein and communicating therewith, an injector outlet adjacent the front end of the tank,

and a pipe for supplying steam to the auxiliary tank, such pipe extending longitudinally of the auxiliary tank with its outlet end directed toward the injector outlet whereby the incoming steam carries the water in the auxiliary tank toward the said injector outlet.

6. In combination in a locomotive feed water heating system having an injector feed means, a main tank, an auxiliary tank of less capacity than the main tank and communicating therewith so that a free flow of water from the main tank to the auxiliary tank is permitted, a steam pipe from the locomotive for supplying heat to the auxiliary tank, a controlling valve in the said pipe, a pilot valve for controlling the operation of the controlling valve, a thermostatic means in the auxiliary tank for controlling the operation of the pilot valve, and a supply pipe leading from the auxiliary tank to the said injector feed means.

7 In combination in a locomotive feed water heating system having an injector feed means, a main tank, an auxiliary tank of less capacity than the main tank and communicating therewith so that a free flow of water from the main tank to the auxiliary tank is permitted, a steam pipe from the locomotive for supplying heat to the auxiliary tank, a controlling valve in the said pipe, a thermostatic means in the auxiliary tank for controlling the operation of the controlling valve and a supply pipe leading from the auxiliary tank to the sald injector feed means.

In testimony whereof I have hereunto signed my name in the presence of the two subscribed witnesses.

THORWALD E. GRAHN.

Witnesses:

IDA MAY BLAINE, L. A. MYERS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

